This invention relates to a clamping apparatus for use in releasably grasping a load to be lifted from two or more sides of the load.
Various clamping apparatuses have been developed for use in lifting loads. Among these clamping apparatuses are ones having a plurality of clamping arms which can releasably grasp a load to be lifted from multiple sides. In some cases, the clamping arms pivot between an open and closed position. In other cases, the clamping arms translate without pivoting along a linear or other path between an open and closed position.
With clamping apparatuses of the type having movable clamping arms which have been proposed in the past, the height of the load that can be lifted by the clamping arms is limited by the length of the clamping arms. The taller is the load, the longer the clamping arms need to be. As the clamping arms become longer, the clamping apparatus as a whole becomes more bulky and more difficult to maneuver. In addition, as the length of the clamping arms increases, the bending moments applied to the clamping arms increase, and the clamping arms need to be heavier to resist the increased bending moments. Furthermore, the longer are the clamping arms, the higher the clamping apparatus must be lifted in order to clear the top of a load to be lifted or in order to avoid collisions with other items when the clamping apparatus is being transported or maneuvered. This imposes limitations on the equipment used to manipulate the clamping apparatus and the height of the workplace in which the clamping apparatus is used.